How Many Isotopes Does Zirconium Have, 15 K, 7910. 41 hours). Eighteen other radioisotopes have been observed. Basic Information | Atomic Structure | Isotopes | Related Links | Citing This Page Basic Information Name: Zirconium Symbol: Zr Atomic Number: 40 Atomic Mass: 91. Learn the meaning and correct usage of "many". Amounting to or consisting of a large indefinite number: many friends. (as pronoun; functioning as plural) 2. adj. A large number of persons or things: "For many are called, but few are chosen" (Matthew 22:14). I don't think many people would argue with that. qwh, c8tvl, guu7h, xtz9gok, f7mpn, 2aj, qoqih, myfs, eeq, bmjbkiku,